Our invention has to do with the features of electrical devices that save battery power. Also, more specifically, this invention describes an electrical arrangement to save battery power for a laptop computer. Even more specifically, this invention describes a new and useful sleep-mode indicator system for the laptop computer.
Portable devices such as portable computers, personal digital assistants (PDAs), and cellular telephones are very common products today. They, like other portable devices, are primarily designed to operate in different locations and under various environmental conditions. Unlike equipment designed to operate in a fixed location such as a desk top computer, a portable device relies mostly on portable power supply such as batteries for operation. For such a device, electrical power usage is always a significant concern. The more a portable device uses electrical power per unit time, the faster its battery power supply is drained. On the one hand, factors such as internal circuit elements, device shape and size to a great extent determine how much electrical power per unit time is needed to operate the device. On the other hand, power usage is a significant concern also because its battery power continues to be drained whenever the device is ON. This holds true whether or not the entire device is being operated on at the time or is being left idle and unused.
Saving electrical power has been a very important goal ever since the birth of battery-operated portable devices. For example, for laptop computers, one efficient way is to apply battery power only to the parts of a device in use, and at the same time to withhold power from those parts of a device not in use. The early portable devices, however, had a simple ON/OFF arrangement in which full battery power was available for use when the devices were ON and the battery power was completely shut off when the devices were OFF. Information such as re-usable programs and data saved in the semiconductor memories became lost once the devices were turned OFF. To use the programs and data again, additional power and time must be used to load them back into the semiconductor memories. Some later portable device used non-volatile semiconductor memories so that the saved information remains intact even when the devices were turned OFF; some other portable devices used stand-by power adapted to keep the memories refreshed when the devices were OFF.
Today""s laptop computers have complicated circuitry because of their additional peripheral units such as floppy disk, hard disk, PCMCIA and CD drives. To efficiently manage the use of electrical power, arrangements have been devised to monitor various functions inside a laptop computer. The computer is intelligent enough to apply battery power only to internal circuits and sub-systems that are deemed xe2x80x98in usexe2x80x99 and at the same time to withhold power from those circuits and sub-systems that are deemed xe2x80x98idlexe2x80x99. Sometimes the power is not completely withheld from the xe2x80x98idlexe2x80x99 circuitry but the power supply is merely reduced due to its entry into a low power consumption mode. Either way, the power management arrangement inside the laptop computer maximizes the computer""s power savings and lengthens the duration the laptop computer can operate using batteries.
The electrical state of the computer when the power management arrangement deprives or reduces electrical power supplied to the xe2x80x98idlexe2x80x99 circuitry and sub-systems is generally referred to as the sleep mode. During sleep mode, the arrangement further monitors the activities in the computer in order that power can be applied immediately when needed. One way a laptop computer enters into the sleep mode is through user inaction. For example, when there is no user key entry for a pre-determined duration, display circuitry and related-subsystems are then shut off, and relevant programs and data are saved. Another way is through user issuance of a sleep command, and another way is through the detection of battery charge below a set level.
A blinking sleep-mode indicator typically identifies to users that the laptop computer is in sleep mode. One such indicator is a blinking LED located on computer housing for convenient observation. To awaken the computer from sleep mode, a typical way is by pressing any key on the keyboard. In this manner, relevant programs and data need not be re-loaded from hard disk and power to an otherwise idle display is conserved.
Unfortunately, once the computer enters into sleep mode, the sleep-mode indicator system is turned ON, and the indicator LED will and continue to blink until the computer exits the sleep mode. The computer does not have any intelligence in knowing when to leave ON the indicator system and when to turn it OFF during sleep mode. For example, better intelligence is needed during sleep mode in the situations where the user has gone to sleep or is otherwise unavailable for a lengthy period of time. Such intelligence can allow the computer to shut down the indicator system even during sleep mode. In this manner, although the power saving over any single day might be miniscule, however, the power savings would be very significant for many users who prefer to have their computers ON day in and day out.
Therefore, it is an aspect of the present invention to provide better intelligence to an electrical device such as a laptop computer as to when during sleep mode the user is unavailable to operate the device. Briefly, an arrangement is provided to allow a user to specify time periods of unavailability such as typical sleeping hours, lunch hour, etc. If a specified time period occurs during the device sleep mode, then the sleep-mode indicator system is turned OFF until the specified period is over.
It is another aspect of the present invention in that the sleep-mode indicator system is not turned OFF for a specified time period of a particular day should the device not be in sleep mode at the beginning time of the specified time period. Further, the indicator system is not turned OFF any more for the rest of the specified time period of that day should the computer is subsequently caused to exit sleep mode temporarily during that specified time period.